javascript - to redirect the same page after form submit -

i have form in webpage index.html. when submit form redirects action page.

i want page redirect (index.html) after completing action.

<div class="container">     <div class="row marginbot-80">         <div class="col-md-8 col-md-offset-2">             <form id="contact-form" method="post" action="mailfunc.php" class="wow bounceinup" data-wow-offset="10" data-wow-delay="0.2s">                 <div class="row marginbot-20">                     <div class="col-md-6 xs-marginbot-20">                         <input type="text" class="form-control input-lg" id="name" placeholder="enter name" required="required" />                     </div>                     <div class="col-md-6">                         <input type="email" class="form-control input-lg" id="email" placeholder="enter email" required="required" />                     </div>                 </div>                 <div class="row">                     <div class="col-md-12">                         <div class="form-group">                             <input type="text" class="form-control input-lg" id="subject" placeholder="subject" required="required" />                         </div>                         <div class="form-group">                             <textarea name="message" id="message" class="form-control" rows="4" cols="25" required="required" placeholder="message"></textarea>                         </div>                         <button "style=width:40 height:40" class="btn btn-skin" type="submit" id="btncontactus">send message</button>                     </div>                 </div>             </form>         </div>     </div> </div> 

you redirect after script in mailfunc.php index.html this:

header("location: index.html"); exit();